In modern internal combustion engines, devices for variably adjusting the control times of gas exchange valves are used to be able to variably adjust the phase relation between a crankshaft and a camshaft in a defined angular range, between a maximum advanced position and a maximum retarded position. The device is integrated into a drive train by means of which torque is transmitted from the crankshaft to the camshaft. This drive train may be implemented, for example, as a belt drive, chain drive or gearwheel drive. Furthermore, the device is connected in a rotationally fixed fashion to a camshaft and can have, for example, one or more pressure chambers by means of which the phase relation between the crankshaft and the camshaft can be varied selectively by applying a pressure medium.
A device of this type is known, for example, from DE 10 2006 020 314 A1. The device has a drive element, an output element and two side covers, wherein the drive element has a driven connection from a crankshaft, and the output element is attached in a rotationally fixed fashion to a camshaft. The output element is arranged so as to be pivotable with respect to the drive element in a predefined angular interval. The drive element, the output element and the side covers bound a plurality of pressure spaces which are divided by vanes into pressure chambers which act against one another. The pressure chambers form a hydraulic actuator drive by means of which the phase angle between the output element and the drive element can be adjusted in a variable fashion. The side covers are arranged on the axial side faces of the output element and of the drive element and are connected in a rotationally fixed fashion to the drive element by means of screws. In order to apply pressure medium to the pressure chambers, drilled holes are provided in the output element, said drilled holes starting from a central opening in the output element, running in the radial direction and opening into the pressure chambers.
The device has a locking mechanism which comprises a sliding guide and a spring-loaded locking element. The sliding guide is formed by a depression in the side cover which is embodied as a solid cast part and a hardened insertion element which is arranged in the depression. In order to ensure a flush termination between the axial side face of the side cover and the insertion element, the depression must be worked in a metal-cutting manner. The locking element is arranged in an axially displaceable fashion inside a receptacle which is formed inside the output element. If the sliding guide and the locking element are located axially opposite one another, the locking element can engage in the sliding guide and couple the output element mechanically to the drive element. In order to release the locked connection, the sliding guide is provided with pressure medium which forces the locking element back into the receptacle. The insertion element makes available a stop face for the locking element, with the result that only the insertion element has to have a high degree of strength and the side cover can be fabricated from more cost-effective materials. The application of force by the insertion element to the side cover is done via contact over a surface, with the result that the load at this point is smaller than in the case of the linear contact between the locking element and the insertion element.